A level site consists of 3 m of clay of unit weight 19 kN/m3 and coefficient of earth pressure of 0.7.
The water table is at a depth of 1 m. Compute the effective normal stress and the shear stress acting on a plane rotated 60 degrees clockwise from the horizontal at a depth of 2.5 m in this deposit.
It may be assumed that the clay has the same density both above and below the water table.